Numbat

Myrmecobius fasciatus

Blamed on foxes

IUCN status: Near Threatened

EPBC Predator Threat Rating: Very high/Extreme

IUCN claim: “The introduction of the predatory Red Fox and feral cats has had a profound impact and continues to be a major threat today (Friend 2008).”

Studies in support

A poison-baiting campaign initiated in 1982 was followed by a population increase (Friend 1990) until 1992 (Friend & Thomas 1994), after which the population crashed (Friend & Page 2017).

Studies not in support

Foxes were not the main cause of mortality nor the main predator of reintroduced numbats (Friend & Thomas 1994). Numbats were last confirmed in NSW 3 years before foxes arrived (Current submission).

Is the threat claim evidence-based?

There are no studies evidencing a negative association between numbats and foxes. Poison-baiting is not a reliable proxy for fox abundance. In contradiction with the claim, the extirpation record pre-dates the fox arrival record.

Evidence linking Myrmecobius fasciatus to foxes. A. Systematic review of evidence for an association between Myrmecobius fasciatus and foxes. Positive studies are in support of the hypothesis that foxes contribute to the decline of Myrmecobius fasciatus, negative studies are not in support. Predation studies include studies documenting hunting or scavenging; baiting studies are associations between poison baiting and threatened mammal abundance where information on predator abundance is not provided; population studies are associations between threatened mammal and predator abundance. B. Last records of extirpated populations relative to earliest local records of foxes. Error bars show record uncertainty range. Predator arrival records were digitized from Fairfax 2019.
Evidence linking Myrmecobius fasciatus to foxes. A. Systematic review of evidence for an association between Myrmecobius fasciatus and foxes. Positive studies are in support of the hypothesis that foxes contribute to the decline of Myrmecobius fasciatus, negative studies are not in support. Predation studies include studies documenting hunting or scavenging; baiting studies are associations between poison baiting and threatened mammal abundance where information on predator abundance is not provided; population studies are associations between threatened mammal and predator abundance. B. Last records of extirpated populations relative to earliest local records of foxes. Error bars show record uncertainty range. Predator arrival records were digitized from Fairfax 2019.

References

Current submission (2023) Scant evidence that introduced predators cause extinctions. Conservation Biology

EPBC. (2015) Threat Abatement Plan for Predation by Feral Cats. Environment Protection and Biodiversity Conservation Act 1999, Department of Environment, Government of Australia. (Table A1).

Fairfax, Dispersal of the introduced red fox (Vulpes vulpes) across Australia. Biol. Invasions 21, 1259-1268 (2019).

Friend, J.A. and Thomas, N.D., 1994. Reintroduction and the numbat recovery programme. Reintroduction Biology of Australian and New Zealand Fauna’.(Ed. M. Serena.) pp, pp.189-198.

Friend, J.A., 1990. The numbat Myrmecobius fasciatus (Myrmecobiidae): history of decline and potential for recovery. In Proceedings of the Ecological Society of Australia (Vol. 16, pp. 369-377).

Friend, J.A., Page, M.J., 2017. Numbat (Myrmecobius fasciatus) Recovery Plan. Wildlife Management Program No. 60 in Department of Parks and Wildlife, Western Australia

IUCN Red List. https://www.iucnredlist.org/ Accessed June 2023